Initialise a given graph walk object once, and then keep using it whilst
the same pipeline is running. Once the pipeline is stopped, release the
graph walk object.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This will also mean that the necessary graph related data structures will
be allocated dynamically, removing the need for maximum ID checks.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add media_entity_graph_walk_init() and media_entity_graph_walk_cleanup()
functions in order to dynamically allocate memory for the graph. This is
not done in media_entity_graph_walk_start() as there are situations where
e.g. correct error handling, that itself may not fail, requires successful
graph walk.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The struct media_entity_graph was allocated in the stack, limiting the
number of entities that could be reasonably allocated. Instead, move the
struct to struct media_pipeline which is typically allocated using
kmalloc() instead.

The intent is to keep the enumeration around for later use for the
duration of the streaming. As streaming is eventually stopped, an
unfortunate memory allocation failure would prevent stopping the
streaming. As no memory will need to be allocated, the problem is avoided
altogether.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

KernelDoc doesn't appear to handle anonymous structs defined inside
another gracefully. As the struct is internal to the framework graph walk
algorithm, detailed documentation isn't seen very important.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

It will be needed in struct media_pipeline shortly.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This is useful in e.g. knowing whether certain operations have already
been performed for an entity. The users include the framework itself (for
graph walking) and a number of drivers.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The internal index can be used internally by the framework in order to keep
track of entities for a purpose or another. The internal index is constant
while it's registered to a media device, but the same index may be re-used
once the entity having that index is unregistered.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add a basic documentation for most ancillary functions.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Several additional functions are described at media-entity.c.
Moving them to the header file, to make the code cleaner and
to have all such macros at the same place.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Those media_obj_* functions are actually creating/destroying
media graph objects. So, rename them to better represent
what they're actually doing.

No functional changes.

This was created via this small shell script:

	for i in $(git grep -l media_gobj_init); do sed s,media_gobj_init,media_gobj_create,g <$i >a && mv a $i; done
	for i in $(git grep -l media_gobj_remove); do sed s,media_gobj_remove,media_gobj_destroy,g <$i >a && mv a $i; done
Suggested-by: NSakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that we moved the content of the media-framework.txt into
the kerneldoc documentation, move the per-function specific
documentation to the corresponding functions and clean it up.

It would be good if we had already the markdown kernel-doc
patches merged upstream, but, while we doesn't have it,
let's make it less ugly at device-drivers.xml.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This function was used in the past to free the links
that were allocated by the media controller core.

However, this is not needed anymore. We should likely
get rid of the funcion on some function, but, for now,
let's just convert into an inlined function and let the
compiler to get rid of it.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Both revision and group_id fields were never used and were always
initialized to zero. Remove them.
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

With the MC next gen rework, what's left for media_entity_init()
is to just initialize the PADs. However, certain devices, like
a FLASH led/light doesn't have any input or output PAD.

So, there's no reason why calling media_entity_init() would be
mandatory. Also, despite its name, what this function actually
does is to initialize the PADs data. So, rename it to
media_entity_pads_init() in order to reflect that.

The media entity actual init happens during entity register,
at media_device_register_entity(). We should move init of
num_links and num_backlinks to it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

We should not be creating device nodes at IRQ contexts. So,
the only flags we'll be using will be GFP_KERNEL. Let's
remove the gfp_flags, in order to make the interface simpler.

If we ever need it, it would be easy to revert those changes.

While here, remove an extra blank line.
Suggested-by: NSakari Ailus <sakari.ailus@iki.fi>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Rename the userspace types from MEDIA_ENT_T_ to MEDIA_ENT_F_
and add the backward compatibility bits.

The changes at the .c files was generated by the following
coccinelle script:

@@
@@
-MEDIA_ENT_T_UNKNOWN
+MEDIA_ENT_F_UNKNOWN
@@
@@
-MEDIA_ENT_T_DVB_BASE
+MEDIA_ENT_F_DVB_BASE
@@
@@
-MEDIA_ENT_T_V4L2_BASE
+MEDIA_ENT_F_V4L2_BASE
@@
@@
-MEDIA_ENT_T_V4L2_SUBDEV_BASE
+MEDIA_ENT_F_V4L2_SUBDEV_BASE
@@
@@
-MEDIA_ENT_T_CONNECTOR_BASE
+MEDIA_ENT_F_CONNECTOR_BASE
@@
@@
-MEDIA_ENT_T_V4L2_VIDEO
+MEDIA_ENT_F_IO_V4L
@@
@@
-MEDIA_ENT_T_V4L2_VBI
+MEDIA_ENT_F_IO_VBI
@@
@@
-MEDIA_ENT_T_V4L2_SWRADIO
+MEDIA_ENT_F_IO_SWRADIO
@@
@@
-MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN
+MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN
@@
@@
-MEDIA_ENT_T_CONN_RF
+MEDIA_ENT_F_CONN_RF
@@
@@
-MEDIA_ENT_T_CONN_SVIDEO
+MEDIA_ENT_F_CONN_SVIDEO
@@
@@
-MEDIA_ENT_T_CONN_COMPOSITE
+MEDIA_ENT_F_CONN_COMPOSITE
@@
@@
-MEDIA_ENT_T_CONN_TEST
+MEDIA_ENT_F_CONN_TEST
@@
@@
-MEDIA_ENT_T_V4L2_SUBDEV_SENSOR
+MEDIA_ENT_F_CAM_SENSOR
@@
@@
-MEDIA_ENT_T_V4L2_SUBDEV_FLASH
+MEDIA_ENT_F_FLASH
@@
@@
-MEDIA_ENT_T_V4L2_SUBDEV_LENS
+MEDIA_ENT_F_LENS
@@
@@
-MEDIA_ENT_T_V4L2_SUBDEV_DECODER
+MEDIA_ENT_F_ATV_DECODER
@@
@@
-MEDIA_ENT_T_V4L2_SUBDEV_TUNER
+MEDIA_ENT_F_TUNER
@@
@@
-MEDIA_ENT_T_DVB_DEMOD
+MEDIA_ENT_F_DTV_DEMOD
@@
@@
-MEDIA_ENT_T_DVB_DEMUX
+MEDIA_ENT_F_TS_DEMUX
@@
@@
-MEDIA_ENT_T_DVB_TSOUT
+MEDIA_ENT_F_IO_DTV
@@
@@
-MEDIA_ENT_T_DVB_CA
+MEDIA_ENT_F_DTV_CA
@@
@@
-MEDIA_ENT_T_DVB_NET_DECAP
+MEDIA_ENT_F_DTV_NET_DECAP
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Entities should have one or more functions. Calling it as a
type proofed to not be correct, as an entity could eventually
have more than one type.

So, rename the field as function.

Please notice that this patch doesn't extend support for
multiple function entities. Such change will happen when
we have real case drivers using it.

No functional changes.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Drivers should check if media_create_pad_link() actually
worked.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Drivers should check if interfaces and interface links were
created. Add a must_check for them.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Due to the graph traversal algorithm currently in usage, we
need a copy of all data links. Those backlinks should not be
send to userspace, as otherwise, all links there will be
duplicated.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Only a few structs are documented on kernel-doc-nano format
(the ones added by the MC next gen patches).

Add a documentation for all structs, and ensure that they'll
be producing the documentation at the Kernel's device driver
DocBook.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Just like what's done with entities, when the media controller is
unregistered, release any interface and interface links that
might still be there.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add functions to explicitly unregister all entity links.
This function is called automatically when an entity
link is destroyed.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Let's control the topology changes inside the graph_object. So, move the
addition and removal of interfaces/entities from the mdev lists to
media_gobj_init() and media_gobj_remove().

The main reason is that mdev should have lists for all object types, as
the new MC api will require to store objects in separate places.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add a new ioctl that will report the entire topology on
one go.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Don't use anymore the type/subtype entity data/macros
inside the Kernel.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As we'll be removing entity subtypes from the Kernel, we need
to provide a way for drivers and core to check if a given
entity is represented by a V4L2 subdev or if it is an V4L2
I/O entity (typically with DMA).

Drivers that create entities that don't belong to any defined subdev
category should use MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media device should list the interface objects, so add a linked list
for those interfaces in struct media_device.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that we have a new graph object called "interfaces", we
need to be able to link them to the entities.

Add a linked list to the interfaces to allow them to be
linked to the entities.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

By adding an union at media_link, we get for free a way to
represent interface->entity links.

No need to change anything at the code, just at the internal
header file.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The entire logic that represent graph links were developed on a
time where there were no needs to dynamic remove links. So,
although links are created/removed one by one via some
functions, they're stored as an array inside the entity struct.

As the array may grow, there's a logic inside the code that
checks if the amount of space is not enough to store
the needed links. If it isn't the core uses krealloc()
to change the size of the link, with is bad, as it
leaves the memory fragmented.

So, convert links into a list.

Also, currently,  both source and sink entities need the link
at the graph traversal logic inside media_entity. So there's
a logic duplicating all links. That makes it to spend
twice the memory needed. This is not a big deal for today's
usage, where the number of links are not big.

Yet, if during the MC workshop discussions, it was said that
IIO graphs could have up to 4,000 entities. So, we may
want to remove the duplication on some future. The problem
is that it would require a separate linked list to store
the backlinks inside the entity, or to use a more complex
algorithm to do graph backlink traversal, with is something
that the current graph traversal inside the core can't cope
with. So, let's postpone a such change if/when it is actually
needed.

It should also be noticed that the media_link structure uses
44 bytes on 32-bit architectures and 84 bytes on 64-bit
architecture. It will thus be allocated out of the 64-bytes and
96-bytes pools respectively. That's a 12.5% memory waste on
64-bit architectures and 31.25% on 32-bit architecture.
A linked list is less efficient than an array in this case, but
this could later be optimized if we can get rid of the reverse
links (with would reduce memory allocation by 50%).
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Interfaces are different than entities: they represent a
Kernel<->userspace interaction, while entities represent a
piece of hardware/firmware/software that executes a function.

Let's distinguish them by creating a separate structure to
store the interfaces.

Later patches should change the existing drivers and logic
to split the current interface embedded inside the entity
structure (device nodes) into a separate object of the graph.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that the struct media_entity .parent field is unused, it can be
safely removed. Since all the previous users were converted to use
the .mdev field from the embedded struct media_gobj instead.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

With the new API, a link can be either between two PADs or between an interface
and an entity. So, we need to use a better name for the function that create
links between two pads.

So, rename the such function to media_create_pad_link().

No functional changes.

This patch was created via this shell script:
	for i in $(find drivers/media -name '*.[ch]' -type f) $(find drivers/staging/media -name '*.[ch]' -type f) $(find include/ -name '*.h' -type f) ; do sed s,media_entity_create_link,media_create_pad_link,g <$i >a && mv a $i; done
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

It helps to check if the media controller is doing the
right thing with the object creation and removal.

No extra code/data will be produced if DEBUG or
CONFIG_DYNAMIC_DEBUG is not enabled.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Just like entities and pads, links also need to have unique
Object IDs along a given media controller.

So, let's add a media_gobj inside it and initialize
the object then a new link is created.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

PADs also need unique object IDs that won't conflict with
the entity object IDs.

The pad objects are currently created via media_entity_init()
and, once created, never change.

While this will likely change in the future in order to
support dynamic changes, for now we'll keep PADs as arrays
and initialize the media_gobj embedded structs when
registering the entity.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As entities are graph objects, let's embed media_gobj
on it. That ensures an unique ID for entities that can be
global along the entire media controller.

For now, we'll keep the already existing entity ID. Such
field need to be dropped at some point, but for now, let's
not do this, to avoid needing to review all drivers and
the userspace apps.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Due to the MC API proposed changes, we'll need to have an unique
object ID for all graph objects, and have some shared fields
that will be common on all media graph objects.

Right now, the only common object is the object ID, but other
fields will be added later on.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>